As known by owners of small pets, particularly cats, the excretions or waste materials of these animals, such as urine and feces, produce foul odors, especially when permitted to stand for any appreciable amount of time. Many attempts have been made in the art to solve this problem. One of the more popular approaches generally taken has been to attempt to train or encourage the pet to routinely contain these activities in one predetermine place within a dwelling. This approach has been successful to some extent by providing boxes or shallow containers filled with commercially available litter material which tend to absorb the urine and feces, and to that extent, assist in controlling the odors. This approach, however, is not fully effective, and the odor problem may be acute, especially in small confined apartments where the litter box must, by necessity, be located in areas shared with the pets' owners.
Another approach to addressing the odor problem is to train the pet to leave the premises or dwelling prior to excretion. To eliminate the annoyance and inconvenience of having the pet owner open and close the door each time the pet wants in or out, devices, such as a hatch (e.g., see U.S. Pat. No. 3,091,221), a windowgate (e.g., see U.S. Pat. No. 3,499.246), or similar small door apparatus (e.g., see U.S. Pat. No. 3,690,299) permit the passage of a pet out of a dwelling or other structure. These devices are only useful when located at or near ground level, and are not as useful when used in apartments where windows and doors are substantially above ground level, unless a balcony or like exit exists. These types of devices do not confine the pet once it leaves the dwelling, and this risk may expose the pet to danger and injury and may well permit the pet to wander away or otherwise become lost. Typically, these devices are necessarily mounted in a wall of the dwelling which somewhat limits the flexibility of these devices to be moved from one location to another.
Another attempt to solve the odor problem associated with urine and feces excretions and to contain unpleasant odors in a litter box device is disclosed in U.S. Pat. No. 4,029,048 (which issued to Gershbein). The Gershbein device features a housing having an opening large enough for a pet to enter and exit and a flexible closure mounted adjacent to the opening which has flexible sections which overlap sufficiently in a sheet-like fashion to form a wall. The pet can enter through this opening and use the litter tray placed inside the device. Although the device has a closure on the opening, as the pet enters or exits the device through the closure, odor naturally escapes from the device. In addition, the front panel must be pivotally opened for access to the litter tray when cleaning and maintenance is required.
As a consequence, while the problems of odor control and minimization of messes associated with the indoor house pets have been known for many years, attempts to address these shortcomings of available litter services and the like have fallen short.